drm/vc4: vec: Support progressive modes

The VEC is able to output progressive analog modes, but the driver has
never set the proper bit to do so.
Signed-off-by: Mateusz Kwiatkowski <kfyatek+publicgit@gmail.com>
Link: https://lore.kernel.org/r/20221207-rpi-hvs-crtc-misc-v1-15-1f8e0770798b@cerno.techSigned-off-by: Maxime Ripard <maxime@cerno.tech>

drivers/gpu/drm/vc4/vc4_vec.c

@@ -613,7 +613,9 @@ static void vc4_vec_encoder_enable(struct drm_encoder *encoder,
 	VEC_WRITE(VEC_CLMP0_START, 0xac);
 	VEC_WRITE(VEC_CLMP0_END, 0xec);
 	VEC_WRITE(VEC_CONFIG2,
-		  VEC_CONFIG2_UV_DIG_DIS | VEC_CONFIG2_RGB_DIG_DIS);
+		  VEC_CONFIG2_UV_DIG_DIS |
+		  VEC_CONFIG2_RGB_DIG_DIS |
+		  ((adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE) ? 0 : VEC_CONFIG2_PROG_SCAN));
 	VEC_WRITE(VEC_CONFIG3, VEC_CONFIG3_HORIZ_LEN_STD);
 	VEC_WRITE(VEC_DAC_CONFIG, vec->variant->dac_config);